A month after Geron quit the human embryonic stem cell (hESC) business, there are still no takers for the program. The decision was just named the "Stem Cell Misstep of the Year" by Paul Knoepfler, stem-cell scientist and blogger, who said it "bordered on the unethical."

Canadian bioethicist Françoise Baylis agrees, in an essay in Bioethics Forum. She points out that Geron's chief medical officer asserted that they would monitor the patients, and report the results, which would be "a fair reflection of what would have happened if we had completed the study." But the study was designed for 10 patients, and only four had begun treatment when the company pulled the plug. "No clinical trial," she notes, "should involve too few or too many participants." She explains:

It is important that the trial not be underpowered and thus unable to generate scientific knowledge. It is equally important than no more research participants than necessary be exposed to potential research risks. If only five participants were needed to generate the scientific knowledge, then why would Geron and the F.D.A. have agreed to expose additional persons to the potential harms of trial participation?

On the other hand, if…the findings from five research participants will be underpowered, then they may have been exposed to the potential harms of trial participation without the potential for benefit in the form of scientific knowledge.

Ethically, it is even more problematic, as another Canadian, Marleen Eijkholt, has stressed, that a fifth patient received the treatment after the cancellation was announced. Katie Sharify just became front-page news in the San Francisco Chronicle, in an article titled "Keeping Hope Alive." She pledges to stop being "this shallow girl [who] only cared about my hair and makeup and going to clubs," and to become a spokesperson advocating for stem cell research.

Her courage and determination are admirable, but the article unknowingly raises questions about the validity of her informed consent. According to the story, both Sharify and her family were uneasy about the experiment and unsure whether she should take part, until the surgeon from Stanford who would be injecting the actual stem cells convinced her the night before the procedure. "After talking to him, I knew this was a really big deal," Sharify said. "I'd been trying to find the reason all of this happened to me."

The California Institute for Regenerative Medicine (CIRM) remains officially "optimistic" about the technology. Though their human pluripotent stem cell (hPSC) initiative now seems to focus on reprogramming cells, embryonic stem cells "are not excluded from the effort."